The present invention relates to an electronic key device, and more particularly, to an electronic key device for automobiles.
In addition to higher performance and improved safety, convenience is important in automobiles. For example, a smart entry apparatus that uses an electronic key device has been proposed. With this apparatus, an automobile door is automatically unlocked when a person holding the electronic key device approaches the automobile. The door is locked automatically when the person holding the electronic key walks away from the automobile.
A typical smart entry apparatus is activated by an electronic key device. The electronic key device includes a housing that contains a battery holder, which holds a battery functioning as a power source, a substrate, to which integrated circuits are attached to achieve the necessary smart entry functions, and a key, which is used during abnormal states such as when the battery runs out of power. Further, the electronic key device includes a first locking member, which holds the key in a retracted position when the key is not in use, and a second locking member, which holds the key in an extended position, in which the key is ready for use.
When an abnormality occurs, such as when the battery runs out of power, the smart entry apparatus may not function properly. In such case, the key, which is normally retracted, is extended from the housing. Thus, the key may be inserted into a keyhole to lock or unlock the door. In this case, the first locking member releases and extends the key from the housing. The second locking member then functions to hold the key in the extended position.
In the prior art, the battery holder is removed from the housing to replace the battery. The battery holder is located in a cavity defined in the housing. The cavity is closed by a cap, which is always locked except when the battery is being replaced. A third locking member is provided to keep the cap locked.
In this structure, the first locking member is needed to hold the key in a locked position when the key is not in use, the second locking member is needed when the key is in a position to be used, and the third locking member is needed to keep the cap of the cavity closed. The locking members increase the number of required parts. This complicates the manufacture of the electronic key device and increases costs. Further, the three locking members occupy space and thus make miniaturization difficult.
It is an object of the invention to provide a compact electronic key device. It is another object of the present invention to provide an electronic key device that can be manufactured easily and inexpensively.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, an electronic key device incorporating electronic components is provided. The device includes a housing, a battery holder for holding the battery, a key fitted in the key retainer, and a locking member. The housing has a cavity for containing a battery, which supplies power to the electronic components, and a key retainer. The battery holder is inserted into the cavity. The key is movable between a retracted position and an extended position. The battery holder is locked to and released from the housing by the locking member. The key is locked by the locking member when located in the extended position.